Well cleaning system



Nov. 29, 1938.

J. GRANT WELL CLEANING SYSTEM Filed June 1'7,` 1935 2 Sheets-Sheet l Nov. 29, v1938. J. GRANT WELL CLEANING SYSTEM Filed June 17, 1955 2 Sheets-Sheet 2 Patented Nov. 29, 1938 UNITED STATES WELLy CLEANING SYSTEM John Grant, Losangeies, oeuf.

Application June 17,

. 6 Claims.

'Ihis invention deals vgenerally with well cleaning systems, particularly of the type wherein there is utilized a device provided witha low pressure or charge receiving chamber having a 5 normally closedinlet adapted to be opened at a predetermined point in the well, whereby the well uid, under relatively high pressure, charges the chamber with sand or other foreign matter adjacent theinlet, or sets up such pressure actions l or high velocity uid movements as to dislodge foreign matter which may be olering obstruction to free passage of iluid through ssures in the formation or perforations in the well casing. The

invention will here be described as applied to thel l cleaning of casing perforations, to which use it is particularly well adapted, but this particularized description is not to be considered as in any way limitative'on the adaptability of the invention for other well cleaning operations.

Ihe usual type of well cleaning device may be described generally as consisting of relatively moving parts, one of which is adapted to engage and remain substantially stationary relative to the casing, and the other part, which usually contains the charge receiving chamber, being movable relative to the part being retained in engagement with the casing. The charge receiving chamber is rendered more or less suddenly communicable with the Well fluid by providing a closure adapted to be opened as a result of relative movement between the cleaner parts to which I have referred. Briefly, in a well cleaning operation inv which this customary type of cleaner is used, the well cleaning device, including the as-V sembly of relatively movable parts, is lowered in the well to the depth of the zone to be.cleaned, and then the cleaner is operated by way of the suspension means to produce relative movement of the parts to open the charge receiving chamber closure.

The invention dilers primarily from the customary practice as mentioned above in that it involves a distinct change in well cleaner construction and, as a result, departure from the 41 general methods heretofore employed. Instead of incorporating in a unitized cleaner construction the two general relatively movable parts referred to above, including a section adapted to engage the casing and perform the function, among others, of an abutment acting to open the charge receiving chamber'closure upon relative movement of the other section, I make the abutment entirely separate from the charge receiving section of the cleaner, but yet maintain essentially the same operative relationship between 1935, vSclt'al No.v 26,916

(Cl. 16S- 19) the two. According to the present system, the casing engaging section, hereinafter referred to as the abutment, is rst lowered to the desired depth in the well, separately from the cleaner proper, and the latter is then lowered into engagement with the. abutment to open the low pressure` chamber closure and perform the cleanl ing operation.

chamber containing the' charge may be removed from the well separately from the abutment, and subsequently run back into the well and the operation repeated as many times as maybe desired, without having to remove the abutment. In thismanner considerable time may be saved throughout the course of a. series of individual cleaning operations. Moreover, the usual liability of accidentally tripping the device to prematurely open the charge receiving chamber is avoided in that by reason of the separate sectional characteristics of the apparatus, by no possibility can the chamber become opened until the section containing the chamber reaches a predetermined position of engagementvwith the abutment.

All the above and various additional features `and objects of the invention will be understood to best advantage from the following detailed de- .'scription of the invention in oneof its typical and preferred forms. Reference is made throughout the description to the accompanying drawings ;I in which:

Fig. 1 is a general view, mainly in elevation, showing' the abutment lowered in the well casing and engaged by a tool for removal from the well;

Fig. 2 is a sectional View showing a typical well cleaning device in engagement and operative relationship with the abutment. l

Fig. 3 is a downward continuation of Fig. 2 showing the lowerportion of the abutment;

Fig. 4 is a fragmentary View, partly in section, showing the upper charge receiving portion of the well cleaner body;

Figs. 5 and 6 are sectional views taken on lines 5 5 and 6-,6 of Figs. 2v and 3, respectively; and

Fig. '7 is an elevation showing a variational form of the invention 'in which the abutment is suspended in the Well on the lower end of a pipe string.

In the drawings, I have indicated at l0 a typical form of abutment, which, as previously mentioned, is adapted to be lowered in the well casing ll to a predetermined position-opposite the particular group of casing perforations l2 to be cleaned. After theabutment has been set in proper position, a suitable well cleaning device,

Thereafter, the section of the typified by the showing at I3,' is lowered into engagement and predetermined operative relationship with the abutment I0, causing the closure means for the charge receiving chamber in theA well cleaning device I3 to be opened and a charge of well uid, together with particles clogging the' casing perforations, to be drawn up wardly into the chamber, all in the manner herecasing I I, and vertically confining, the annular spaceiI9 between the body I4-and casing II. I have here shown packers to be of a solid rubber type having, in the case of packer I1, beveled end portions I1a clamped between couplings 20 and I5 provided4 with beveledsurfaces at 20a and I5a engaging the beveled ends of the packer. As shown in Fig. 3, packer I8 is similarly confined between coupling I6 and a shoe 2I threaded at 22' on the lower end of the body and having a fluid passage 23.

For the purpose of enabling well liquid to be by-passed around the packers as the abutment is raised or-lowered in the well, I provide one or more by-pass tubes 24, two being shown typically, extending at their lower ends throughthrough tubes 24 and passage 23 as the abutment is raised, and in a reverse direction while the abutment is being lowered.

`As will later appear, the typical form of well cleaning device here illustrated is adapted to be operated to open communication between the charge receiving chamber and the interior of abutment I0, by virtue of Vrelative vertical movementbetween the cleaning device and abutmentcasing.` The typical form of retaining means il lustrated comprises a plurality of radially compressible, bowed spring elements 28 fastened at their ends to sleeves 29 surrounding the body I4 at spaced points between couplings I5 and I6. One or both of the sleeves 29 may be capable of lmovement longitudinally of the body to permit radial flexing of the spring elements 28.

The intermediate section of the body between the packers I1 and I8 is also provided with a series of apertures 30 through which the cleaning device I3 acts todraw liquid from space I9' into .the body passage 3| and thence upwardly lthrough vertical bores 32, see Fig. 5, into the charge receiving chamber D of the cleaning device. Coupling 20 of the abutment carries an upward tubular extension 33 adapted to receive the lower end of the cleaning device I3, therepreferably being provided with tube 33 a suitablefo'rm of packing or sealing means acting to maintain the abutment and cleaning device in substantially iluid tight engagement. As typical of such sealing means, I show a tubular rubber insert 34 within the lower portion-of tube 33 and having a ange 34a clamped between the lower end of the tube and the base of counterbore 35 of coupling 20.- For the purpose of facilitating removal of the abutment from the well, I may provide on its upper end a suitable attachment that is readily engageable and retained by, for example, a shing tool to be lowered in the well. Such attachment may consist, typically, of 'a socket 36 threaded on the upper end of tube 33,

and having a Idownwardly angular shoulder 31 form of bailer or cleaning device I3 is to be .rei garded merely as typical 'of a variety of such devices capable of cooperation with the abutis not to be regarded as limited by the showing of the specific form illustrated. Body portion 4I of the cleaning device comprises a series of threadably connected sections 42, 43 and 44, section 42 (Fig. 4) serving as a head or top closure for the low pressure or charge receiving chamber D. Attachment section 45 connected to section 42 serves as a means whereby the body may be attached to a suspensionelement, as for example cable 46. Section 43, here shown as longitudinally contracted, may be of any desirable length, although a 40 ft; length gives chamber D a capacity ample for most operations.

Section 42 has a reduced axial bore 41 from which extends a transverse passage 4,8 controlled by a spring closed, outwardly opening relief -valve generally indicated at 49. The function of this valve is merel-y to relieve high pressure in the charge receiving chamber as the. tool is raised into zones of lower pressure. i To facilitate unfloading of chamber D, I preferably provide an inwardly opening, spring closed dump relief ,valve at 50. This valve is fully described in the copending application of Weldon C. Erwin, et al,

on Well Bailers, filed April 22, 1933, Ser. No.-

667,439 now Patent No. 2,059,629, granted November 3, '1936. It will suice here to state that removable screw'plug 5I normally closespassage 52 and that when chamber D is to be unloaded, plug 5I is removed so that valve 50 may open to relieve the lowered pressure in the chamber (caused by dumping the fluid) by bleeding air in through a passage 20.

A removable dump door 52 is provided in section 44 of the body, the construction and mounting ofthis door being fully described in said copending application, Ser. No. 667,439; and requiring for present purposes no further description other than to mention its removability to dumpthe charge from chamber D following a ,cleaning operation and after the device has been elevated to th'e ground surface. Screwed into and depending from section 44 is a tubular section 53 which may be considered a part of the charge into chamber D, and thereafter seats to trap the charge in the chamber for removal from the well. Charge receiving chamberD is normally closed at its lower end by a frangible disk 55vclamped between a disk carrying member 56 and bushing 51- inserted within-bore 58 of section 53.

Carried within the lower end of the cleaner body is a. disk breaking member |55 in the form of a tubular plunger capable of limited vertical movement within section 53. Provision is made for such relative movement by a pin and slot connection at |56 between member |55 and the body, pin |51 terminating in body section 53 and extending through vertical slots .|58 in opposite sides of the disk breaking member. The lowermost position of member |55 relative to the body is limited by the engagement of the upper end of slot |58 with pin |51; the uppermost such relative position of member |55 being limited,

after the disk 55 is broken, by engagement with body shoulder 59.

Tubular shoe 60 is threaded at 6| into the lower end of the disk breaking member |55, the shoe Y carrying a packing ring .62 confined between shoulder 60h and the lower end of member |55. The diameter of shoe 6|] is such that the shoe will have a sliding it within the abutment liner 31% when inserted therein as shown in Fig. 2, so that between the liner and packing ring 62 there will be a substantially iluid tight iit, thereby preventing lany appreciable portion of the charge to be taken into chamber D from being drawn i-n through the space 64 between the cleaner and abutment section 33.

In performing a cleaning operation, the abutment lll is first lowered or pushed down within the casing to the depth of that particular portion of the casing to be cleaned. The abutment may be thus lowered in any suitable manner, as for example by pushing it ahead of a weighted body (not shown) lowered on the end of a cable. After the abutment has been placed, the lowering means is withdrawn and the cleaning device I3 lowered on cable 46 into-the casing. Upon coming into engagement with the upper end of the abutment, the lower end of the cleaner I3 is guided into tubular portion 33 by the inclined surfaces 31a and 31h within socket member 36. The shoe 60 enters packing liner 34 (the upper end of which is beveled at 34h to insure entry of the cleaner shoe) and moves down into engagement with the end of bore 35 in the coupling 2li. While the cleaner I3 is being lowered, disk breaking member |55 and the shoe 6l! are supported by pin |51, the latter being in engagement with the upper end of slots |58.

After shoe 6U seats within the abutment in the position illustrated, the body Portion of the cleaner continues its downward movement, dropping disk 55 against the upper toothed end |55a of the breaking member, pin |51 having sucient downward travel within slots |58 to allow member |55 to penetrate' and break the disk. Prefer'- ably the cleaning device I3 will be lowered rapidly within the well so that after downward movement of the disk breaking member |55 has become arrested, the disk 55 will be impacted against its upper end with suicient force to break the disk. It is o f course apparent that if the disk fails to break, the cleaning device may be withdrawn from the abutment and again dropped into engagement therewith, in the manner explained, until the disk is-broken.

Immediately upon breaking the disk, a sudden pressure differential is imposed between the outside and inside of the casing vbetween packers |'1 and |8, with the result that there occurs a sudden rush of well fluid through the casing perforations 2, acting to dislodge and carry into lspace I9 particles clogging the perforations. 'I'he fluid is thence drawn through the abutment body openings 30 into passage 3| and thence upwardly through bores 32, 60a, the interior o'f the disk breaking member |55, and past valve 54 into the charge receiving chamber D. After the4 full charge has been taken in and a substantial pressure balance exists between the chamber D and the formation pressure acting to flow the charge into chamber, valve 54 seats to trap the charge in the cleaning device. The' latter then'is withdrawn from the well and the charge dumped in the manner previously explained. After a new disk 55 has Vbeen placed in the cleaningdevice,

the latter may be again lowered to perform another cleaning operation with the abutment l0 remaining in substantially the same position; or after one or a number of individual cleaning operations, the abutment may be shifted vertically within the casing by suitable means manip-' ulated from the ground surface, to bring the abutment opposite a successive section of the casing. At the completion of the cleaning operations, the abutment assembly |0 may be removed from the well by means of suitable tool, such as the fishing tool 39 shown in Fig. 1.

In accordance with the method as described in the foregoing, the abutment used has been separated and disconnected from any suspension or lowering means other than those required for the-initial lowering, nal removal, or vertical here, since the abutment is supported on the pipe string, spring elements 28 may be dispensed with, as well as socket 36 on the upper end of section 33'.

I claim:

1'. Well cleaning apparatus, comprising a selfcontained abutment adapted to be lowered into and retainedfin engagement with the well casing at any predetermined level, said abutment having a packer making'substantially fluid tight engagement with the casing and having a welluid passage leading from a point at one side of the packer to a point above the packer at the upper end of the abutment; and a cleaning device adapted to be lowered and raised in the well independently of the abutment, said device having a low pressure chamber with an inlet passage, and a closure normally closing said in'- let passage;` cooperating means on the abutment and cleaning device to interconnect the abutm`ent .passage with the chamber inlet passage when the cleaning device is lowered into contact with the abutment; and means operable'by virtue of said contact to open the chamber inlet closire. l

. the previously described combination except that l2. Well cleaning apparatus comprising a self contained abutment adapted to be lowered-into -and retained in engagement with the well casing at any predetermined depth, said vabutment comprising a tubular body, a pair of packers carried at longitudinally spaced points on said body,

there being fluid passing apertures in the body- 3. In well cleaning apparatus, the combination comprising, a self contained tubular abut' ment adapted to be lowered into and retained in engagement with the well casing at any predetermined depth, a separate well cleaning ldevice adapted to be subsequently lowered in the well into engagement with said abutment, said device including a body having a low pressure chgamber and normally' closed means adapted to be opened toA admit well fluid tosaid chamber, and cooperatingmeans on said body and abutment for opening said means, the last mentioned means including means for restricting the flow f well uid between said cleaning device and abutment into said chamber.

4. In well cleaning apparatus', the combination comprising, a self contained tubular abutment adapted to be lowered into and retained in Vengagement with the well casing at any predetermined depth, a separate Well cleaning device adapted to be subsequently lowered in the well into engagement with saidl abutment, said del vice including a body having a low pressure chamberand normally closed means adapted to be l opened to admit well uid to said chamber, and

cooperating means on said body and abutment for o pening said means by virtue of impacting movement of said body downward against the abutment, the last mentioned means including means for restricting the ow of well uid between said cleaning device and abutment into' said chamber.

5. Well cleaning apparatus comprising a'self contained abutment adapted to be lowered into gagement with the well casing at any predeter-` mined depth, said abutment comprising a tubular body, a pair of packers carried at longitudinally spaced points on said body, there being fluid passing apertures. in the body between said packers, a separate well cleaning device adapted to be subsequently loweredA in the Well into engagement with said abutment, said device including a body having a low pressure chamber and normally closed means adapted to be opened to admit well f uid tosaid chamber, and cooperating means on said body and abutment for opening said means, the last mentioned means including means for restricting the flow of well` fluid between said cleaning devicer and abutment into said chamber.

- JOHN GRANT. 

